For several years now, "Downton Abbey" historical advisor Alastair Bruce has tried his best to make sure that all the details incorporated into the show—from house decorations, fashions, and even dialogue—fit a 1912 setting.

However, there was one thing he could not touch on—Christianity. Bruce has been directed by executives in charge of the series to "leave religion out of it," and many fans of the show have noticed it, too, according to The Telegraph.

The Crawley family has never been seen in the process of sitting down to dinner, said Bruce, in order to avoid showing the characters saying grace.

"In essence you hardly ever see a table that isn't already sat at. We never see the beginning of a luncheon or a dinner, because no one was ever allowed to see a grace being said, and I would never allow them to sit down without having said grace," Bruce explained.

Bruce really wanted to incorporate prayers into the show, but all of his suggestions were shot down. "I suggested a Latin grace, but they decided that was too far, and no one would've known what was going on," he said.

The show's higher ups were so insistent about not incorporating religion that even table napkins folded in the shape of a bishop's mitre were not spared. "Everyone panics when you try to do anything religious on the telly," he said. "I still wish we could've got some decent napkin folds, but I was always left with my triangle."

There is only one more episode left for "Downton Abbey" Season 6, which is the Christmas special. Bruce said a lot of surprises still await fans, and they should be prepared for anything.

"It is going to end in a way that you might not expect. It will be both exciting and emotional and it will leave you thinking lots of things," he guaranteed.